The present invention refers to a device for introducing and/or collecting, in non-surgical way, fluids that may contain or not, cells in the inside of the uterus of a mammal, the device being able to penetrate through the cervix duct (uterus neck) and to reach the uterus horns, in a simple and quick manner without the need of sedation or anesthesia. The invention further refers to a method of using the device, and to a probe being useful for the device.
The invention is preferably applicable in porcine livestock for introducing a fluid of spermatozoids, embryos or therapeutic solutions into the anterior third of a uterus horn near the uterotubal junction , or for obtaining embryos from the upper portions of the uterus horn, in a sow.
The invention may also be applied to small ruminants such as sheep, goats, and other mammal animal species.
For carrying out artificial insemination with a low number of spermatozoids and for performing collection and transfer of embryos, the use of surgical techniques, such as laparotomy, has been well known in the art. These conventional techniques have the inconveniences that they are traumatically invasive and require a high degree of specialization of the veterinarians or insemination specialists, appropriate installations for carrying out the technique, and further imply the potential risks to the animal that are inherent to any surgical intervention.
To avoid these inconveniences, non-surgical systems have been developed. However, these systems have been limited to those species as for example bovine and equine animals, in view that the use thereof does not present difficulties due to the large body volume and anatomic configuration of these species. In other species, as for example in porcine animals or in small ruminants, non-surgical systems have only had a minor implementation due to the difficulties encountered in passing through the cervix duct and reaching deep uterine positions, due to that in these animal species the cervix duct has a series of protuberances that render introduction of a probe considerably difficult. This circumstance has hindered practical application of embryo transfer and has limited artificial insemination to the deposition of semen samples to deep vaginal or to cervix level and always requiting a high amount of spermatozoids. Practical application of other biotechniques such as cryopreservation of sperms, preselection of the sex by sperm separation, embryo micromanipulation etc. has been limited by this circumstance.
Specifically in the porcine species, attempts have been made to develop no-surgical rigid systems aimed to pass through the cervical canal and to reach the uterus. Some of these systems comprise a device including a tube or catheter having a proximal end which includes a widened portion for simplifying handling thereof, and the outer surface of the distal end of which includes a spiral portion that permits its introduction and fixing of the device within the entry of the cervix duct and to thereby reach the uterus body. Through the inside of the tube, a probe is introduced. Due to the configuration, these known devices do normally not penetrate further than into the initial portion of the uterus horns.
These devices can only be introduced with difficulties without harming the protuberances of the cervix duct. Moreover they may perforate the wall of the cervix or of the uterus. Such known systems are described for example in WO-A-9714365, U.S. Pat. No. 5,916,144 and WO-A-9927868.
To solve the aforestated inconveniences, the present invention refers to a new device and method that allow, without the need of sedation or anesthesia of the animal, to introduce a fluid with spermatozoids, embryos or therapeutic solutions into the anterior third portion of a uterus horn near the uterotubal junction or which, according to an embodiment thereof allows to collect embryos from the upper portions of the uterus horn.
For this purpose, the device of the invention, the same as the conventional ones, comprises a tube or catheter having a proximal end which includes a widened portion for simplifying handling of the device, and a distal end having an outer surface that includes a spiral portion that enables introduction and fixing of the tube within the entry of the cervix duct, and a probe slidably housed within the tube.
In accordance with the invention the probe is comprised of a flexible tubular body comprising a longitudinal chamber, and at least one flexible duct within the longitudinal chamber in the flexible tubular body, the outside of the flexible tubular body being of a flexible material of plastic or of any other flexible material having an outer surface that allows the probe to slide within the female reproduction apparatus without causing any harm to the mucous membranes. This structure allows the probe to be inserted through the proximal end of the tube, and to be pushed towards the distal end of the tube so that, after it has reached said distal end, it emerges therefrom such that it first advances through the cervix duct and then enters the uterus horn.
Another feature of the invention resides in the fact that connecting means for connecting a tap having at least one way are provided at the proximal end of the probe, said connecting means for enabling introduction and/or collection of fluids.
According to the invention, the probe has a consistency and a resilience being sufficient to allow that, after emerging from the distal end of the tube, it may progress through the cervix duct and through the uterus horn. Thus, in accordance with the invention, the probe has a relationship resilience (=elasticity)/consistency (=stiffness) such that, a longitudinal section of 5 cm length of the probe is able to bend 30xc2x0 to 160xc2x0, particularly 100xc2x0 to 150xc2x0, preferably 135xc2x0 to 145xc2x0 and particularly 140xc2x0, and such that a longitudinal section of 8 to 10 cm length of the probe resists a load of 1.5 to 4.5N, particularly of about 3N, without bending when the load is applied perpendicularly on the longitudinal section i.e. it has an axial penetration strength of 15 to 45N, particularly about 3N, for a longitudinal section of 10 cm before starting to bend.
In one embodiment of the probe, the flexible tubular body is made of a plastic material as for example a polymer or copolymer such as thermoplastic polyolefin, elastomer, propylene copolymers and other conventional suitable plastic materials which, at the required thickness of the wall of the flexible tubular body, may comply of the aforementioned relationship resilience/consistency.
In another embodiment of the probe, the flexible tubular body is made of a flexible plastic material of the aforementioned type which, however, as such has a higher resilience and/or a lower consistency than those of the hereinabove mentioned the relationship resilience/consistency at the required thickness of the wall of the flexible tubular body, so that the flexible tubular body requires stiffening by alien elements. For this purpose a plurality of flexible longitudinal ribs may be arranged in the longitudinal chamber between the flexible duct and the tubular body, to thereby increase the consistency and to maintain the required resilience of the probe. In an embodiment of the invention, the longitudinal ribs are comprised of steel threads and the longitudinal chamber that includes the steel threads is tubular.
In still another embodiment of the probe, the flexible tubular body is comprised of a helicoidal member such as a spring, made of metal or plastic, the outside of which is covered by a layer of flexible plastic material that allows the probe to slide within the female reproduction apparatus without causing any harm to the mucous membranes of the uterus duct and of the uterus horns.
In still a further embodiment of the probe, the flexible tubular body is comprised of a tubular member of a material such as a plastic or metal, the outer surface of which, as such is insufficiently smooth for sliding within the female reproduction apparatus, and the outside of which is covered by a layer of flexible plastic material that allows the probe to slide within the female reproduction apparatus without causing any harm to the mucous membranes of the uterus body and of the uterus horns.
The distal end of the probe comprises a piece that adapts to the inner space of the flexible tubular body, the piece including an opening that is arranged in axial continuation of the flexible duct for establishing an inlet and/or outlet for the fluids. So as to avoid harm to the mucous membranes, the end of said piece must be smooth and stump.
The coupling means for coupling the tap to proximal end of the probe may be comprised of a piece that, at one end is adapted to the inner space of the flexible tubular body and the flexible duct and, at the other end, is adapted to the tab, so as to allow introduction-extraction of fluids.
In an embodiment of the invention, the probe has two flexible, preferably concentric ducts, one of which, preferably the outer one and in proximity to the distal end of the probe, communicates with an elastic small external coating so that, once the probe has been placed in the uterus horn, the elastic small external coating can be inflated with air through the outer flexible duct so that it swells in a balloon-like manner and thus adapts itself to the wall of the uterus horn thereby preventing a possible reflux through the uterus horn of liquids that have been introduced into the uterus horn, when intrauterine fluids containing embryos are suctioned.
In a preferred embodiment of the invention, the flexible duct communicating with the flexible small external coating, is the longitudinal chamber that includes the longitudinal flexible ribs between which passage of the air towards the flexible small external coating is allowed.
The invention also refers to a method for non-surgical introduction of fluids containing spermatozoids, embryos or therapeutic solutions into the anterior third of a uterus horn or for collecting embryos from the anterior third of the uterus horn of a female mammal by using the afore described device, without the need of sedating the animal and without disturbing its well-being, the method comprising
introducing the tube into the inside of the vagina up to the entry of the cervix duct at which point the tube is rotated in a counterclockwise sense, for producing its advance within the cervix duct of the female animal such that it becomes firmly fixed within the walls thereof,
once fixing has been achieved, inserting the distal end of the flexible probe by the proximal end of the tube until reaching the anterior end of the tube that is anchored in the inside of the of the cervix duct,
slightly rotating the tube to the left and right, and simultaneously pushing the flexible probe until it bypasses the first protuberance of the cervix cavity,
further pushing the flexible probe thereby noting that the flexible probe first advances with some difficulty by the various protuberances of the cervix duct until reaching the uterus body, whereby, once the cervix duct has been overcome, the resistance offered by the protuberances ceases, and the flexible probe advances without difficulty until reaching the upper portions of a uterus horn, and,
once the flexible probe has been introduced into its final position within the uterus horn, injecting or absorbing fluids into or from the uterine environment through the flexible duct by means of a syringe or a similar device coupled to the tap.
In the case that embryos are to be extracted from the uterus, the method further comprises a subsequent step to introducing the probe into the uterus horn, in which step the elastic small external coating is inflated, whereby the coating adapts itself to the inner space of the uterus horn, and thereafter embryos are suctioned from the anterior portion of the uterus horn.
Thus, the device and method of the invention do not require sedation nor anesthesia of the animal as for example a sow. Furthermore, it does not cause any harm to the well-being of the animal, as it does not use any rigid instrument that might harm and/or perforate the walls of the cervix duct, due to that the flexible probe presents a suitable equilibrium between consistency and resilience for passing the cervix duct and reaching the anterior third of a uterus horn without producing apparent damages.
Additionally, the invention has the great advantage that complete introduction of the flexible probe may be achieved in a minimum time (approximately 3 or 4 minutes) and it allows to work with reduced volumes of semen, embryos or therapeutic solutions, at the same time that it is multifunctional in view that it enables introduction of spermatozoids, embryos and therapeutic solutions deep into the uterus, as well as collection of embryos from the anterior portions of the uterus horn.